Probabilistically Based Risk of Exposure to Power Line Magnetic Fields

Abstract

Guidelines of exposure to power line magnetic fields are usually designed on a deterministic basis, making their validity and adequacy somewhat questionable. Based on an overall probabilistic approach, a method for risk assessment of exposure to overhead power line magnetic fields is presented. There are advantages to the probabilistic approach over conventional methods of developing the risk of exposure to overhead power line magnetic fields. In this article, a model is constructed to predict the randomness in power line magnetic fields, taking into account—in addition to line loading—the random nature of the parameters contributing to the temperature of the power line conductors, which in turn, influences the resulting conductor sag. Those parameters include line loading, ambient temperature, solar irradiation, and wind speed. The correlative nature of those parameters is also considered. The model accounts for the likelihood of the effects of those various operational and weather parameters (or variables), thus avoiding inflated risk estimates produced by compounding single-point worst-case values of the input variables and, consequently, leads to an improved risk assessment.

Keywords:

• power lines
• magnetic fields
• risk assessment
• probabilistic modeling